import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import z from "zod";
import { CONFIG } from "../config.js";
import { makeNWSRequest } from "../utils/index.js";
import {
ForecastPeriod,
ForecastResponse,
PointsResponse,
} from "../interfaces/index.js";
export const getForecastTool = (server: McpServer) =>
server.tool(
"get_forecast",
"Get weather forecast for a location",
{
latitude: z
.number()
.min(-90)
.max(90)
.describe("Latitude of the location"),
longitude: z
.number()
.min(-180)
.max(180)
.describe("Longitude of the location"),
},
async ({ latitude, longitude }) => {
// Get grid point data
const pointsUrl = `${CONFIG.NWS_API_BASE}/points/${latitude.toFixed(
4,
)},${longitude.toFixed(4)}`;
const pointsData = await makeNWSRequest<PointsResponse>(pointsUrl);
if (!pointsData) {
return {
content: [
{
type: "text",
text: `Failed to retrieve grid point data for coordinates: ${latitude}, ${longitude}. This location may not be supported by the NWS API (only US locations are supported).`,
},
],
};
}
const forecastUrl = pointsData.properties?.forecast;
if (!forecastUrl) {
return {
content: [
{
type: "text",
text: "Failed to get forecast URL from grid point data",
},
],
};
}
// Get forecast data
const forecastData = await makeNWSRequest<ForecastResponse>(forecastUrl);
if (!forecastData) {
return {
content: [
{
type: "text",
text: "Failed to retrieve forecast data",
},
],
};
}
const periods = forecastData.properties?.periods || [];
if (periods.length === 0) {
return {
content: [
{
type: "text",
text: "No forecast periods available",
},
],
};
}
// Format forecast periods
const formattedForecast = periods.map((period: ForecastPeriod) =>
[
`${period.name || "Unknown"}:`,
`Temperature: ${period.temperature || "Unknown"}°${
period.temperatureUnit || "F"
}`,
`Wind: ${period.windSpeed || "Unknown"} ${
period.windDirection || ""
}`,
`${period.shortForecast || "No forecast available"}`,
"---",
].join("\n"),
);
const forecastText = `Forecast for ${latitude}, ${longitude}:\n\n${formattedForecast.join(
"\n",
)}`;
return {
content: [
{
type: "text",
text: forecastText,
},
],
};
},
);
